It is common practice when mounting a tire on a wheel to apply a lubricant such as a liquid soap solution to the wheel rims. The lubricant permits the beads of the tire to be forced over the wheel rim without damage and assists in forming an air-tight seal between the rims and beads once mounted.
Under high production conditions, such as in the automotive industry, automated equipment is used to perform the lubricating and mounting operations. It is of course desirable that these operations be carried out as quickly as possible to maximize productivity while achieving satisfactory results.
Present high production wheel lubricators spray or brush the lubricant onto the wheel rims while the wheel is spun about its axis of rotation. U.S. Pat. No. 4,723,563 discloses one such apparatus in which the wheel is engaged by a cone and lifted against a rotating drive disk, causing the wheel to spin on its axis while lubricant is sprayed onto the wheel from an adjacent stationary nozzle. A disadvantage of applying the lubricant in this manner is that it is difficult to control the amount and distribution of the lubricant applied. Soap is applied to not only the bead seats where it is needed, but also to the entire circumferential area of the wheel between the bead seats. The application of excess lubricant is wasteful and causes difficulties later on in the assembly process as some of the soap is carried with the wheel and drips off onto other equipment. The excess lubricant also can disrupt proper balancing of the wheel and tire, since the lubricant may be taken into account during balancing and then redistribute or dry, throwing off the balance. Another disadvantage with this approach is that the wheel is caused to rotate several revolutions during soaping, which takes valuable time and requires stoppage of the wheel before transfer to the next station.
Another wheel lubricator applies soap to the beads of wheels in similar manner but using one or two stationary applicator brushes rather than a spray nozzle. Although use of stationary applicator brushes instead of a nozzle lessens the oversoaping problem, it still requires that the wheel be rotated and thus shares the difficulties of the spray nozzle type wheel soaper in this respect.
Wheel lubricating apparatus and method according to the present invention overcomes or greatly minimizes all of the foregoing objections.